Traditionally the two principal methods of producing methyl chloride have been the chlorination of methane and the hydrochlorination of methanol. Each of these processes has certain disadvantages. The chlorination of methane produces hydrogen chloride as a byproduct, and it generates higher chlorinated methane products such as methylene chloride and chloroform. The hydrochlorination of methanol is dependent on the raw material methanol which adds to the cost of process.
Because of the limitations of current technology, several attempts have been made to synthesize methyl chloride from carbon monoxide, hydrogen, and hydrogen chloride. Such a process would have the benefit of using synthesis gas as a raw material and could utilize byproduct hydrogen chloride from other processes. Four U.S. patents disclose such processes to make methyl chloride: U.S. Pat. Nos. 4,041,087, 4,538,011, 4,845,064, and 4,962,247.
Although the results of these investigations are encouraging, in each case they suffer from serious drawbacks. Uniformly their conversions are limited. In addition, the yields of methyl chloride are reduced due to the production of byproducts. Furthermore, processing conditions are highly corrosive. Finally, the use of precious metals in the catalysts adds to the manufacturing costs.
An object of the present invention is to avoid the disadvantages of the prior art by providing a superior process for the manufacture of methyl halide from carbon monoxide, hydrogen, and hydrogen halide. A further object is to achieve high conversions and maximum yields. A still further object of the present invention to provide a process that is efficient, reliable, safe, and environmentally friendly. These and other objects, features and advantages will be apparent from the following description.